Water Management Considerations for CCR Unit Closure during Plant Closure

The closure of Coal Combustion Residual (CCR) units during plant decommissioning introduces complex water management challenges that are critical to achieving regulatory compliance, environmental protection, and long-term site sustainability. Effective water management strategies must address stormwater and contact water control throughout the closure timeline, while aligning with future site use objectives and sustainability goals. This presentation provides a technical framework for integrating water management into CCR closure planning and execution. Key topics include: • Stormwater Management During Closure and Post-Closure: Design considerations for drainage systems, erosion control, and hydraulic performance under evolving site conditions. • Contact Water Generation and Treatment: Strategies for minimizing contact water during excavation and grading, and treatment system design for compliance with NPDES and CCR regulations. • Transient Hydrology in Staged Closure: Modeling runoff and infiltration during phased construction activities to prevent uncontrolled discharges. • Plant Changes: Considering loss of large flows through the system and how that may affect both water quality and quantity that may be relied on for overall treatment. • Extreme Precipitation and Seasonal Variability: Incorporating climate resilience and probabilistic storm event analysis into closure design. • Sustainability and Future Land Use: Aligning water management systems with post-closure land development and minimizing lifecycle costs. By implementing a comprehensive water management plan, stormwater and contact water controls can be holistically integrated into the closure process — often spanning multiple years. This approach reduces design rework, mitigates environmental risks, and ensures sustainable outcomes for CCR unit closure within the broader context of plant shutdown.